// Copyright (c) 2013 The LevelDB Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file. See the AUTHORS file for names of contributors.

// Test for issue 200: when iterator switches direction from backward
// to forward, the current key can be yielded unexpectedly if a new
// mutation has been added just before the current key.

#include "gtest/gtest.h"
#include "leveldb/db.h"
#include "util/testutil.h"

namespace leveldb
{

    TEST(Issue200, Test)
    {
        // Get rid of any state from an old run.
        std::string dbpath = testing::TempDir() + "leveldb_issue200_test";
        DestroyDB(dbpath, Options());

        DB *db;
        Options options;
        options.create_if_missing = true;
        ASSERT_LEVELDB_OK(DB::Open(options, dbpath, &db));

        WriteOptions write_options;
        ASSERT_LEVELDB_OK(db->Put(write_options, "1", "b"));
        ASSERT_LEVELDB_OK(db->Put(write_options, "2", "c"));
        ASSERT_LEVELDB_OK(db->Put(write_options, "3", "d"));
        ASSERT_LEVELDB_OK(db->Put(write_options, "4", "e"));
        ASSERT_LEVELDB_OK(db->Put(write_options, "5", "f"));

        ReadOptions read_options;
        Iterator *iter = db->NewIterator(read_options);

        // Add an element that should not be reflected in the iterator.
        ASSERT_LEVELDB_OK(db->Put(write_options, "25", "cd"));

        iter->Seek("5");
        ASSERT_EQ(iter->key().ToString(), "5");
        iter->Prev();
        ASSERT_EQ(iter->key().ToString(), "4");
        iter->Prev();
        ASSERT_EQ(iter->key().ToString(), "3");
        iter->Next();
        ASSERT_EQ(iter->key().ToString(), "4");
        iter->Next();
        ASSERT_EQ(iter->key().ToString(), "5");

        delete iter;
        delete db;
        DestroyDB(dbpath, options);
    }

} // namespace leveldb

int main(int argc, char **argv)
{
    testing::InitGoogleTest(&argc, argv);
    return RUN_ALL_TESTS();
}
